The present invention is related to an improved torque wrench in which the central push rod has an escape section. After the torque value of the torque wrench is adjusted, a toothed section of the central push rod is disengaged from a toothed hole of the adjustment handle of the torque wrench. At this time, the escape section of the central push rod gets into the toothed hole so that the central push rod is free from the adjustment handle. Accordingly, when operating the torque wrench, the central push rod will not be driven by the adjustment handle so that the torque value of the torque wrench will not be unexpectedly changed.
FIG. 1 shows a conventional adjustable torque wrench. The wrench main body 1 has a working head section 11 at one end. A central push rod 12 and an adjustment handle 13 are adjustably mounted in the other end of the wrench main body 10. A restricting member 14 is locked on the central push rod to connect one end of the central push rod 12 with the adjustment handle 13. When rotating the adjustment handle 13, the central push rod 12 is rotated along with the adjustment handle 13 so as to adjust the torque value of the torque wrench.
The conventional adjustable torque wrench has some shortcomings in use. For example, after the adjustment handle 13 is rotated to a certain torque scale relative to the wrench main body 10, the adjustment handle 13 is locked. However, in operation of the torque wrench, a user will hold the adjustment handle 13 and apply a force thereon. Under such circumstance, the torque value of the torque wrench is often unexpectedly changed. As a result, the user needs to repeatedly adjust the torque value of the torque wrench. Moreover, when applying the force onto the adjustment handle in operation, the locking structure of the adjustment handle tends to break and damage.